46
11-5. TROUBLE CRITERION OF MAIN PARTS
MXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA
Normal
Discharge temperature
thermistor (RT62)
Fin temperature
thermistor (RT64)
Measure the resistance using a tester. (Part temperature: 14°F ~ 104°F)
Part name
Check method and criterion
1.2 k
Ω
~1.56 k
Ω
Measure the resistance between terminals using a tester.
(Winding temperature: 14°F ~ 104°F)
Compressor
Measure the resistance between lead wires using a tester.
(Part temperature: 14°F ~ 104°F)
Outdoor fan motor
R.V. coil
Measure the resistance using a tester. (Part temperature: 14°F ~ 104°F)
13.4
Ω
~ 16.4
Ω
Normal (Each phase)
13
Ω
~ 16
Ω
MXZ-2B20NA - MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA
Defrost thermistor (RT61)
Ambient temperature
thermistor (RT65)
Outdoor heat exchanger
temperature thermistor
(RT68)
Measure the resistance with a tester.
Refer to 11-7. “Test point diagram and voltage”,1. “Outdoor electronic control P. C.
board”, or 3. “Outdoor power board” , for the chart of thermistor.
Measure the resistance with a tester.
Before measurement, hold the thermistor with your hands to warm it up.
Refer to 11-7. “Test point diagram and voltage”,1. “Outdoor electronic control P. C.
board”, for the chart of thermistor.
MXZ-2B20NA
0.86
Ω
~ 1.06
Ω
1.29
Ω
~ 1.49
Ω
MXZ-2B20NA
MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA
Normal (Each phase)
MXZ-2B20NA
MXZ-2B20NA -
MXZ-3B24NA
MXZ-3B30NA
MXZ-4B36NA
1
Linear expansion valve
LEV
WHT
RED
YLW BRN
ORN
BLU
The other models
WHT - RED
RED - ORN
37.4
Ω
~ 53.9
Ω
Normal
YLW -
- BLU
Color of lead wire
MXZ-2B20NA
WHT - RED
RED - ORN
YLW - RED
RED - BLU
BRN
BRN
High pressure switch
(HPS)
MXZ-3B24NA
MXZ-3B30NA
MXZ-4B36NA
Pressure
Normal
HPS
537 ± 22 PSIG
696 PSIG
Open
Close
+ 7
-
15
1
W
U
V
WHT
RED
BLK
U
RED
WHT
BLK
V
W
(W)
(V)
(U)
LEV
WHT
RED
YLW
ORN
BLU
